Calculating machine



June 23, 1936. R. MULLER CALCULATING MACHINE Filed July '7, 1934 2 Sheets-Sheet 1 INVENTOR FMe/TAmU/er M wfm June 23, 1936. R. L. MULLER CALCULATING MACHINE Filed July '7, 1954 2 Sheets-Sheet 2 BY fl w I V q ATTORN EYS Patented June 23, 1936 PATENT OFFICE CALCULATING MACHINE Robert L. Muller, Detroit, Mich, assignor to Burroughs Adding Machine Company, Detroit, Mich., a corporation of Michigan Application July 7. 1934. Serial No. 734,079

2 Claims.

This invention relates to calculating machines and is particularly adaptable to key responsive calculators.

In many uses of calculating machines it is de- 5 sirable to selectively and accumulatively count only certain items entered in the machine; A key responsive or key-driven calculator, because of its manner of operation, presents many problems and diificulties to overcome, not present in other 10 types of machines, in providing a counting mechanism therefor. In a machine of this type the keys do not have to be depressed in any particular order, that is, the keys may be depressed in any order or sequence whatever, as long as all the 5 proper digits are depressed for the amount to be entered. For instance, if an amount of 125 is to be entered in the machine, the operator may depress first the units key which in this case is 5 or the hundreds key, which in this case is 1 followed by depression of either of the other two keys. Therefore a counting mechanism cannot be employed which is actuated as the result of a depression of any particular key such as a. units key or of any particular key of a certain bank because the counting device must be operated only after the last key has been depressed in any given amount entered in the machine, regardless of in which column that key may be. It is the purpose of this invention, therefore, to provide a counting device that will count the number of amounts entered into the machine regardless of the number of digits contained in each amount entered and of the order in which they are entered and accumulate and count only such items as selected by the operator and only after the last key of the amount has been depressed thereby entering the amount.

.Other objects of this invention, their results and advantages will be apparent from the follow- 40 ing description given in connection with the drawings in which,-

Figure 1 is a perspective view of an automatic key-driven calculator constructed in accordance with .this invention, and 45 Fig. 2 is a transverse vertical section taken through the machine.

General calculating features The calculator is provided with a full keyboard having depressible amount of digit keys l0 arranged in banks and projecting through the upper keyboard plate H. The keys are normally urged upward by compression springs l3 and are pro- 5 vided with laterally extending projections l4 adapted to engage upwardly extending lugs 16 formed on index bars I! when the keys are depressed. There is an index bar I! for each bank of keys. The lower ends of keys Ill engage slots I8 10 formed in slides I9 and move the slides rearward against the tension of springs 2| when the keys are depressed. There is also a slide l9 and spring 2| for each bank of keys. Each slide 19 has a downwardly projecting finger 22 adapted to engage 1!! cross bail 23 pivoted to both sides of the machine and spring urged clockwise against fingers 22. Bail 23 has a downwardly extending arm 25 adapted to engage and close a pair of switch contacts 26 connected in a motor circuit for starting and stopping the driving motor M. The switch is normally disengaged by the urge of bail 23 which is spring actuated in a clockwise direction. 3 Upon depression of any key III' the bail is rocked and the switch contacts closed to start the motor.

Motor M through its shaft and a train of gears (not shown) drives the main operating shaft 29 which extends across the entire width of the machine. Fixed to shaft 29 in each of the various banks of the machine is a toothed ratchet disk 31 which is rotated counterclockwise as viewed in Fig. 2 by motor M. A pawl 32 engages each ratchet 3| under certain conditions to connect its index bar I! to its ratchet 3| so as to be driven by motor M. For this purpose each slide I9 is connected 5 by an arm 33 to a latch mechanism 34 as shown in the heretofore mentioned Patent No. 1,909,714, which mechanism normallyholds pawl 32 disengaged from ratchet disk 3|, but which upon depression of an amount key and the resulting rearward movement of slide l9 releases the latch mechanism 34 to permit pawl 32 to engage ratchet 3|. Pawl 32 is pivoted to a lever 35 pivoted adjacent its lower end about shaft 29 and urged clockwise thereabout by spring 36.

The forward end of index bar I1 is pivotally connected to a toothed actuator rack 40 en aging a gear 4| which through suitable pawls and gears not shown engages and rotates the register pinions 41. It will be understood that there is a pinion 41 for each bank of amount keys, the plurality of pinions making up the registering mechanism as a. whole. The register pinions are visible through a sight opening 48 in a casing 49.

- posts 5| Accumulating operation Upon depression of an amount key M, slide l9 is moved rearwardly thereby connecting the motor contact to start the motor which in turn drives the index bar I! forward, the pawl 32 having been released by movement of latch 34. Bar ll moves forward until it is stopped by the depressed amount key, which is locked in depressed condition. Upon forward movement of index bar H, the register pinions are not moved, but upon return movement of the index bar H the pinions are rotated clockwise to accumulate the amount entered into the register by the depression of the amount keys.

To clear or zeroize the register pinions ill, it is only necessary to depress the clearing key (2' which through a mechanism shown in the heretofore mentioned Pasinski patent and in the Horton Patent No. 1,326,504, zeroizes or clears the entire register pinions, that is the register pinions are released and are returned to zero position by spring means.

Counting selected entries As previously stated, because of the fact that a multiple digit amount may be entered in the machine by depression of the necessary digit keys in any order, it is not possible to have a counting mechanism actuated by any particular bank or order of the machine. Accordingly, the three right banks or columns of the machine are employed as a counting section and the key stems and keys for these banks are omitted with the exception of the units key in the right bank. A counter bar or plate is employed for depressing this key and for this purpose is mounted over the I key indicated by reference character ill of the right bank. The plate extends over that portion of the keyboard which otherwise would be occupied by the three right banks for the full depth of the keyboard. The plate is hinged at its upper and lower left corners upon carried by the keyboard plate i I. Downward movement of the plate is limited by a post 52 extending upwardly from the upper key plate I i and having a rubber cushion 53 in its upper end. The plate is normally urged to upper or counterclockwise position by the key stem spring l3 of the key i ll upon which it rests and is limited in its counterclockwise movement by a hook 54 which extends from the rear of the plate and engages the post 5i.

By extending the plate the full depth of the keyboard and over the full three key banks, operation of the counting section is facilitated as it is very simple and convenient for the operator to slide his hand over and touch the plate at any point to depress it without appreciable interruption to calculating movements.

Upon depression of plate 5d, the key iiiis depressed and the register pinion of that bank is rotated through an are representing one unit. Accordingly, after a series of entries have been made the three right register pinions will indicate the total count of the selected items which the operator has elected to count by manual depression. of plate 5d and the remaining banks to the left willindicate the total of the amounts entered into the machine. Obviously, the operator may depress the keys to the left of the count section in any order desired, after which thecount section bar or plate 5d may be depressed once to count the entry or item.

From the foregoing description, it will be rapparent that there has been provided a counting mechanism particularly adapted for a key operated or key responsive type of calculator in which amounts may be accumulated in the amount section and in which selected entries may be counted in the right section or three right banks without, of course, interfering with the accumulating in the amount section, regardless of the order of depression of the keys for entering any given multiple digit amount in the amount section. The invention provides a very simple mechanism which is foolproof and permits of very rapid operation without appreciably slowing up calculations on the machine. Because of the size of the plate 50, it is substantially impossible to miss the plate and very unlikely that any other key will be depressed as may be the case if one small key only were used as the counting medium.

It will be obvious to those skilled in the art that many changes may be made in the details of construction without departing from the spirit and scope of this invention as defined in the appended claims.

I claim:

1. The combination in a key responsive calculator having a keyboard comprising aplurality of rows of amount keys of different numerical orders, a register having a plurality of pinions corresponding to the orders of said keyboard, a tens-transfer mechanism for said register, and means for immediately operating said register pinions in response to depression of said keys of a count device applicable to the machine without changing the construction thereof, said device comprising a plate movably mounted on said keyboard at the side thereof so that it may be easily moved by a turn of an operator's hand from any position over the keys of said keyboard, said plate covering a predetermined number of orders of said keyboard and being connected to mechanism causing, upon movement of said plate, an immediate movement of one step of the register pinion corresponding to the lowest order covered by said plate, whereby items may be entered on said keyboard and in a portion of said register and a count of said items readily kept in another portion of said register by striking said plate at the time of the entry of each item.

2. The combination in a key responsive calculator having a keyboard comprising a plurality of rows of amount keys of different numerical orders, a register having a plurality of pinions corresponding to the orders of said keyboard, a tens-transfer mechanism for said register, and means for immediately operating said register pinions in response to a depression of said keys; of a plate pivoted on said keyboard at the side thereof so that it may be easily rocked by a turn of an operators hand from any position over the keys of said keyboard, said plate being pivoted adjacent a predetermined intermediate row of keys and extending over the orders of said machine toward one side of said keyboard and operating only the units key in the units order to thereby cause an immediate movement of one step of the register pinion corresponding to the lowest order covered by said plate, whereby items may be entered on said keys and in a portion of said register and a count of said items readilykept in another portion of said register by rocking said plate at the time of the entry of each item.

RUBER'I' L. 

